2.6.37-stable review patch. If anyone has any objections, please let us know.
------------------ From: Sarah Sharp <[email protected]> commit a6d940dd759bf240d28624198660ed34582a327b upstream. When xhci_discover_or_reset_device() is called after a host controller power loss, the virtual device may need to be reallocated. Make sure xhci_alloc_dev() uses GFP_NOIO. This avoid causing a deadlock by allowing the kernel to flush pending I/O while reallocating memory for a virtual device for a USB mass storage device that's holding the backing store for dirty memory buffers. This patch should be queued for the 2.6.37 stable tree. Signed-off-by: Sarah Sharp <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/usb/host/xhci.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -2431,8 +2431,12 @@ int xhci_alloc_dev(struct usb_hcd *hcd, xhci_err(xhci, "Error while assigning device slot ID\n"); return 0; } - /* xhci_alloc_virt_device() does not touch rings; no need to lock */ - if (!xhci_alloc_virt_device(xhci, xhci->slot_id, udev, GFP_KERNEL)) { + /* xhci_alloc_virt_device() does not touch rings; no need to lock. + * Use GFP_NOIO, since this function can be called from + * xhci_discover_or_reset_device(), which may be called as part of + * mass storage driver error handling. + */ + if (!xhci_alloc_virt_device(xhci, xhci->slot_id, udev, GFP_NOIO)) { /* Disable slot, if we can do it without mem alloc */ xhci_warn(xhci, "Could not allocate xHCI USB device data structures\n"); spin_lock_irqsave(&xhci->lock, flags); _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
